The US National Institutes of Health (NIH) has announced a new $24 million program to develop drugs for rare diseases.

Nearly 90% of potential drugs get ruled out via expensive testing during costly preclinical trials, often dubbed the 'Valley of Death'. For common diseases, going through the valley pays off for pharmaceutical developers. But, drugs for rare diseases seldom have such a payoff, even with incentives offered through the US 1983 Orphan Drug Act.

The new NIH project, called the Therapeutics for Rare and Neglected Diseases program, seeks to set up its own pipeline of facilities and collaborating academic researchers to conduct preclinical and clinical testing.

The project, announced 20 May, is in the early stages of planning, said Stephen Groft, director of the NIH Office of Rare Diseases Research, which oversees the new program. It is currently assembling advisory boards to decide which diseases will be pursued and how to best implement the research.

The NIH estimates that there are more than 6,800 diseases in America that individually affect fewer than 200,000 people but collectively affect more than 25 million. Only about 200 of these diseases have a drug treatment.